Process of bleaching material



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as Waist cuw UNITED STATES PATENT 'OFFICEy HARRY B. SMITH, 0F ALBANY, YORK.

No Drawing.

To'aZZ w from it may concern:

Be it known that I. HARRY SMI'rH, a citizen of the United'States, and a residentof Albany, in .the county of Albany and State of New York, have invented certain new and useful Improvements in Processes of Bleaching Material, of which the following is a speclfication.

My invention relates to a process of' bleaching cotton and other material,

One of the objects of the invention 1S. to provide an improved process of bleaching such material. which is'simp'le, eflicie-nt and requires only. a relatively short time.

The kind of material to which this process is primarily adapted is unbleached cotton goods containing motes, shives and (or) leaf. The process is applicable, however, to any material containing vegetable or animal fibre, such as any class of cotton goods or I yarns, wool, silk, fibre silk or mixtures of same.

The process herein disclosed is more economical and eflicient than processes heretofore used because the removal of the motes, shives and (or) leaf, the bleaching'by an oxidizing agent and the bluing are. effected more or less at the same time. In

United States Patent No. 1499.745, to Irwin J. Smith and myself, there is disclosed aprocess of'dyeing in which increased economy is effected by removing the motes, shive's and (or) leaf by an oxidizing bath which is markedly alkaline,jto which bath a dye is added while the material is still in the solution. In the process of the said patent, however, any tendency to bleach is only incidental, the whole process being carried out solely from the standpoint of removing the motes, shives and (or) leaf without injury to the material and dyeing the same, and the reagents and their strength are chosen ac cordingly. The process herein described and claimed is primarily to obtain a clean, white, bleached material.

Other objects. features and advantages of my invention will appear more fully in the following detailed description and appended claims. 7

In accordance with my invention, I employ an alkaline oxidizing agent which is preferably composed of about half-each'of peroxide of sodium and a salt-of an alkali metal, such as sodium chloride, soda ash, silicate of soda, caustic soda, phosphate of and (or) leaf is relatively short.

. raocnss or BLEAcHI Ie MATERIAL.

Specification of Letterskatent, P,tentd J 24 1922 Appl ication filed July t9, 1921'. Serial I fo. 485,983. I

soda, alone, or a mixture of any'of these salts. The combined weight of the peroxide and salt lof an alkali metal is of sodium preferably. aboutv seven per cent of the weight of the cotton material under treatment. A solution of these chemicals is strongly alkaline and at the same time .oxidizing. Because it is strongly alkaline the time required forremoving the motes, shives At the same time the alkalinity is notsuificient ly intense to harden the material to be bleached, This'solution has been found to operate with entire satisfaction, but,.it is understood that any oxygenliberating product, but preferably those corresponding to the per salts and preferably fora purpose hereinbefore stated, along with the salt of an alkali metal will give satisfactory results. ,For instancaLperoxidanfhydrogen,

percarbonate of sodium, persulphate of so mixture of salts such as those mentioned above. I have, however, obtained the best results with peroxide of sodium.

The dyes preferably used for bluing are alkali blues, inasmuch as they are substantially operatively unaffected by the oxygen yielding compounds and alkalis which are used in the process. I have, for example, employed in practice as a suitable dye that having the trade name Alkali Blue R. S.. These dyes and their chemical composition are well known in the art. They are acid dyes, that is. they require an acid to render them effective. Such dyes cause a very brilliant whiteness vin the bleached material. lVhile various acids might be used for this purpose, I; preferably use an organic acid, such as acetic acid. attack the fibre of the cotton and gives very satisfactory results in bluing. F urthermore, by .its reactionwith the sodium peroxide or its equivalent, it liberates oxygen while the bath is at a 'higlrtemperature, which greatly assists the bleaching operation. At the same time it destroys the organic coloring matter in the cotton, thereby increasing the whiteness of the material.

I have found it preferable in my practice of the invention to pursue a detailed pro- Such an acid does not BLEACHlNG 6L DYEING; FLUID MES ' "same.

' pended fclai ns T hegoods fror the invention as set forth inthe apare firstwashed With boiling water, as is usual inthe art, to rcmovegreasy or waxy foreign matter from the fibers. The cotton material is then passed into a bath at normal atmospheric temperature containing the alkali blue. About fifty grains of the dye may be used to one-hundred pounds ofthe cotton material, This bath is allowed to work on the material for about fifteen minutes. The acetic acid is then added to the same bath to developthe color; The acetic acid may be in amount about two per cent of the weight of the cotton material. After the acetic acid has been: added,'thebath is allowed to act upon the material about ten minutes longer, aftenjwhichthe bath is brought to a high temperature, preferably between 170- and 180 F ahrenheit. It is unnecessary to bring the bath to a boil and preferablenot to do so. Sodium peroxide and sodium chloride or other alkali metal salt, in the .amounts previously mentioned, are now added and the bath maintained hot, preferablyflbetween 170 and 180 F for-a considerable period oftimeE.,fAn hour and a half isample for this,last;,s"tep. It'is the function i. of the sodiumchloride or other alkali metal salt to aid in the development and fixation of the coloringmatter on thefibre, as-well under- During; .the proces motes, shives and (or) l af are subjected on. chemical action which probably softens and dissolves them. It is-to be ..understood' that the chemicals, includingthebluing, theacid and the proporti" s {of the chemicals and periods of time setforth above," are given as merely examples-and that I am not limited .to the.

Having-described my invention, what I elainias new anddesire to secure by Letters Patent is as follows: 7

.1. The process-of bleaching materialwhich comprises subjecting the material to a bath having added thereto an alkali blue, an orgarlicv acid, and an alkaline oxidizing agent.-

2. "Ihejprocess of bleachingcotton material containing foreignmatter -which com- .prises -bluingthematerial with an acid dye and subjecting the materialntor'an alkaline oxidizing, bath. 3*

"The process of bleaching. cotton matealcontaining I foreign matter which com- 'ises subjecting the material to a hot bath favingjadded thereto an alkali blue,- an .or-

ganlc acidj'an'd an alkaline oxidizing-agent.

i; Thefproces's of bleaching cottonmaterial containing foreign matter which compimses subjecting the material .to aibath heated'to a high temperature below the boiling point and having added --thereto .an-alkali blue, an organic acid, and an alkaline oxidiz ing agent.

' and v(or) leaf in 5. The process of bleaching cotton material containing foreign matter which com prises subjecting the material to a bath heat-- ed to a temperatur above 170 F. and below the boiling point and having added thereto line oxidizing agent. 1

6. The process of bleaching materialwhich comprises subjecting the material to a hot bath havingadded thereto an alkali blue, acetic acid, and an alkaline oxidizing agent.

7. The process of'blea ching cotton material containing motes, fshives and (or)-lea'f an alkali blue. an organic acid, and an alka Search Room which comprises treating the material in-a bathhaving added thereto an acid bluing, an organic acid, and an alkaline oxidizing agent adapted to soften or loosen the motes, shives. and (or) leaf in sa -id bath, the bluing being substantially operatively unaffected by sai alkaline oxidizing agent.

8.- The process of, bleaching cotton v Inaterial containing motes, shives. and (or) leaf which comprises treatin the material in a bath containing an acid bluing, and an organic acid, heating the same, adding to the bath while the material is therein an alkaline oxidizing agent adapted to soften.

or loosen the motes, shives and -(or) leaf in said bath, the bluing being substantially operatively unaffected by said alkalineoxidizing agent, and maintaining the bath heated until the motes,

. shives and .(or)

leaf are substantially removed from the ma teriaL- v -9. The process of bleaching cotton material containing motes, shives and (or) leaf 'which comprises-treating the material in a bath containing'an acid bluing and an vor-.

ganic .acid, heating the same to a tempera ture over 170 F. and below the boilin point, adding to the bath while the materia 1s therein an alkaline oxidizing agent or loosen the motes, shives said bath, the bluing be adapted to soften 'ing substantially oper atively' unaffected by said alkaline oxidizing agent, and maintainmg the. bath heated at approximately the above temperatureuntil the "motes, shives.

and (or) leaf are substantially removed .from the material.

10.; The process of bleaching cotton inst- .terialcontaining motes, shives and (or) leaf i which comprises treating-the material ina bath containing an alkali blue, I acetic acid, then heating the bath without bringing the same to a boil, then adding sothen adding I i dium: peroxide and sodium. chloride, and, maintaining. the' bath I with the material therein at approximately the above tempera time until the-motes, shives and (or) leaf t'erial."

11. The processzof which comprises treatin batlreontainingan alkali are substantially removed from the mablue; then adding bleaching martini; the material in a in sodium peroxide and sodium chloride,

and adding further'heat to the bath with the material therein.

12. The process of bleaching cotton material containing motes, shives and (or) leaf which comprises treating the material in a bath containing an alkali blue, then adding an organic 'acid, then heating the bath, then adding sodium peroxide and sodium chloride, and maintaining the bath with the material therein heated until the motes, shives and (or) leaf are substantially removed from the material.

13. The process of bleaching cotton material containing motes, shives and (or) leaf which comprises treating the material in a bath containing an alkali blue, then adding an organic acid, then heating the bath, then adding sodium peroxide and an alkali metal salt, and maintaining the bath with the material therein heated until the motes, shives and (or) leaf are substantially removed from the material. 4

14. The process of bleaching cotton material containing motes, shives and (or) leaf which comprises treating the material in a bath containing an alkali blue, then adding an organic acid, then heating the bath, then adding an oxygen producing agent and sodium chloride, and maintaining the bath With the materialtherein heated until the motes, shivesand (or) leaf are substantially removed from the material.

15. The rocess of bleaching cotton material containing foreign matter which comprises subjecting the cotton to a bath containing a alkali blue, an organic acid, and an amount of sodium peroxide and sodium chloride equal to approximately 7% of the Weight of the cotton material.

In testimony whereof, I have signed my name to this specification.

HARRY B. SMITH. 

